92 THE USES OF PLANTS. 



ROSACES. 



The use of the oils extracted from Sweet and Bitter 

 Almonds (Amygdalus communis, L., vars. dulcis and 

 amara, DC.) has been already mentioned (p. 59, supra). 

 Under the influence of the organic ferment ' emulsin,' 

 or 'synaptase,' a form of vegetable casein, the crys- 

 talline substance, 'amygdalin,' present in Bitter 

 Almonds, decomposes into prussic acid, oil of bitter 

 almonds, and a glucose, as shown by Liebig and 

 Wohler in 1837 : * 



CaoH^Npn + 2HO = HCN + C r HO + C 19 HO 19 

 Amygdalia Water Prussic Oil of Dextro- 



Acid Bitter Almonds glucose. 



Primus serotina, Ehrhart, the American WILD 

 BLACK CHERRY, the bark of which is there esteemed 

 for its tonic and sedative properties, was introduced to 

 notice by Professor Bentley, in 1863.1 



P. Lauro-cerasus, L., the CHERRY-LAUREL, was 

 admitted into our Pharmacopoeia in 1839, for the 

 manufacture of cherry-laurel water, now superseded 

 by prussic acid. 



Hagenia abyssinica, Willd., ' Koso/ the flowers of 

 which contain an acrid bitter resin, known as Kosin, 

 has been used as a vermifuge. It was introduced here 

 in 18504 and admitted to the Pharmacopoeia in 

 1864. 



Reference will be made in the sequel to the OTTO 

 or ATTAR OF ROSES, prepared from the petals of 



* ' Pharmacographia,' pp. 220-1 ; Bentley and Trimen, ii, pi. 99. 

 f ( Pharm. Journ.,' v (1864), p. 97 ; Bentley and Trimen, ii,pl. 



97- 



J Pereira, 'Pharm. Journ.,' x (1851), p. 15; Bentley and 

 Trimen, ' Medicinal Plants,' ii, pi. 102 ; * Pharmacographia,' pp. 

 228-30. 



